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Comment by nabla9 | Hacker News Reader

  Altitude  Lifetime
  200 km    1 day
  300 km    1 month
  400 km    1 year
  500 km   10 years
  700 km  100 years
  900 km 1000 years

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Ha - and the altitude of the space station is 408 km so most of the junk should clear out in a year? That sounds too easy.

The space station has to add energy almost weekly to overcome drag. If it didn't it would likely come down within a couple years. When they want to throw trash away, they literally just drop it off the side and it burns up eventually: https://gizmodo.com/iss-ditches-2-9-ton-pallet-of-batteries-...

Would that stuff cause a huge fireball in the night sky? 2.9 tons is a hell of a lot of mass... amazing to think it will just burn up in the atmosphere.

I don't think it is to worry about, 1 cubic meter of iron weighs 7.8 tons for example... it is not a huge mass in the end.

I'd say it would burn up pretty nicely. Its not gonna be one homogenous lump of stuff that holds together on re-entry, its a bunch of smaller "things" (battery cells) bundled up and held together with an external shell.

As soon as that shell burns through its going to break apart and each individual part will start burning up.

Yeah probably most of the mass is aluminium sheet which melts quite easily hence Starship and the MiG-25 switching to steel, and also can burn quite well - it was the fuel in the shuttle's boosters.

Because it is really that easy. Space-junk in low-earth orbit is not really a concern, and alarmist articles about space-junk in connection with projects like Starlink are just click-bait that rely on the general public's ignorance of orbital mechanics and space.

Medium and high orbits are a different story. Space junk is absolutely a real concern here.

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